Farm sprayers include large spray tanks which are filled with chemicals from five gallon cans mixed with water in the spray tank. It is important that these spray cans have all of the chemicals removed therefrom to avoid waste and environmental pollution and contamination. A convenient way is needed to puncture an opening in the chemical cans so that cleaning water may be introduced for washing the insides of the cans. The cleaning solution would then be utilized in the spray tank leaving a clean chemical can with no environmental pollution or contamination.